Murata Manufacturing Co., Ltd.

Junya Ago

Michio Kadota

Hideya Horiuchi

Mamoru Ikeura

Takeshi Nakao

Yasuhiro Kuratani

Kazuhiko Morozumi

Seigo Hayashi

Yasunori Takakuwa

Masakazu Mimura

Toshimaro Yoneda

Takao Mukai

Hiroshi Kawai

Yasuhiro Negoro

Shuya Nakao

Haruo Morii

Takahiro Motokawa

Harou Morii

Takeshi Nadota

A multilayer ceramic substrate includes a multilayer composite including a first material layer including glass, a second material layer including a ceramic, disposed in contact with the first material layer, and an internal electrode including an electroconductive material, disposed in contact with at least one of the first material layer and the second material layer. The first material layer is sintered, and is firmly bonded to the second material layer by diffusing or permeating a portion of the glass in the first material layer into the second material layer. The internal electrode includes a main portion and a lead-out portion extending from the main portion to a side surface of the multilayer composite, and the internal electrode includes a ceramic powder at least in the lead-out portion.

Multilayer ceramic substrate, method for manufacturing the same, and piezoelectric resonator component

A method for adjusting a frequency characteristic of an edge reflection type surface acoustic wave device includes the step of obtaining a frequency characteristic of an edge reflection type surface acoustic wave device having a piezoelectric substrate. The edge reflection type surface acoustic wave device has a pair of edges of the piezoelectric substrate which define a predetermined distance therebetween. The piezoelectric substrate is cut at a position which defines a distance that is shorter than the predetermined distance when a final frequency characteristic of the edge reflection type surface acoustic wave device is to be higher than the obtained frequency characteristic. The piezoelectric substrate is cut at a position which defines a distance that is longer than the predetermined distance when a final frequency characteristic of the edge reflection type surface acoustic wave device is to be lower than the obtained frequency characteristic.

Method for producing an edge reflection type surface acoustic wave device

A surface acoustic wave device includes a Y-cut, X-propagation LiTaOsubstrate, at least one interdigital transducer provided on the LiTaOsubstrate and made of Al or a metal containing Al as a major component, and an SiOfilm provided on the surface of the LiTaOsubstrate so as to cover the interdigital transducer, wherein the thickness Hs of the SiOfilm normalized by the wavelength &#x3bb; of a surface acoustic wave and the cut angle &#x3b8; of the LiTaOsubstrate are set to be in any one of the ranges represented by formulae (1) to (8):in the case of 0.00&#x3c;&#x2266;0.05, 30&#xb0;&#x3c;&#x3b8;&#x3c;36&#xb0;&#x2003;&#x2003;(1)in the case of 0.05&#x3c;&#x2266;0.10, 29&#xb0;&#x3c;&#x3b8;&#x3c;36&#xb0;&#x2003;&#x2003;(2)in the case of 0.10&#x3c;&#x2266;0.15, 28&#xb0;&#x3c;&#x3b8;&#x3c;36&#xb0;&#x2003;&#x2003;(3)in the case of 0.15&#x3c;&#x2266;0.20, 27&#xb0;&#x3c;&#x3b8;&#x3c;36&#xb0;&#x2003;&#x2003;(4)in the case of 0.20&#x3c;&#x2266;0.25, 26&#xb0;&#x3c;&#x3b8;&#x3c;36&#xb0;&#x2003;&#x2003;(5)in the case of 0.25&#x3c;&#x2266;0.30, 25&#xb0;&#x3c;&#x3b8;&#x3c;35&#xb0;&#x2003;&#x2003;(6)in the case of 0.30&#x3c;&#x2266;0.35, 23&#xb0;&#x3c;&#x3b8;&#x3c;34&#xb0;&#x2003;&#x2003;(7)in the case of 0.35&#x3c;&#x2266;0.40, 21&#xb0;&#x3c;&#x3b8;&#x3c;31&#xb0;&#x2003;&#x2003;(8)

Surface acoustic wave device

An end-surface reflection type surface acoustic wave filter is capable of increasing an attenuation amount outside a pass band while insertion loss characteristics are not seriously deteriorated. The filter is a longitudinally coupled resonator type surface acoustic wave filter using an SH type surface acoustic wave, which has first and second grooves formed in a piezoelectric substrate at the top surface thereof so as to be substantially parallel to each other and spaced from each other by a predetermined distance. In addition, IDTs which are provided between the grooves for defining the longitudinally coupled resonator type surface acoustic wave filter, reflection end-surfaces disposed on side surfaces of the first and the second grooves at the IDT sides, and one of a resin-coating layer and a protective layer made of SiO , are provided on the top surface of the piezoelectric substrate. The resin-coating layer is arranged to cover at least a region at which the IDTs are located and at least one of the first and the second grooves so as to intrude into one of them, and the protective layer is arranged so as to cover the IDTs.

End-surface reflection type surface acoustic wave filter

A longitudinally coupled resonator-type surface acoustic wave device includes interdigital transducers including a plurality of electrode fingers disposed along the propagation direction of a surface acoustic wave on a surface acoustic wave device. An electrically discontinuous portion is provided in a central portion, in the finger overlap direction, in adjacent electrode fingers in adjacent interdigital transducers, and at least one floating electrode is disposed in the finger overlap direction in the electrically discontinuous portion.

Longitudinally coupled resonator-type surface acoustic wave device

A method of manufacturing an edge reflection type surface acoustic wave device includes the step of preparing a surface acoustic wave mother substrate having a plurality of interdigital transducers formed on one main surface thereof. A cut groove is formed in the substrate by cutting the surface acoustic wave mother substrate beginning from the one main surface side thereof. This step of forming a cut groove is repeated so as to produce a plurality of cut grooves so that the first reflection edge of the respective surface acoustic wave devices are sequentially formed. Next, similarly, cut grooves are sequentially formed on the surface acoustic wave mother substrate from the one main-face side thereof so as not to reach the other main surface thereof, whereby the second reflection edges of the respective surface acoustic wave devices are sequentially formed.

Method of producing edge reflection type surface acoustic wave device

An edge reflection type surface acoustic wave filter includes a piezoelectric substrate having two opposing edges and at least one interdigital transducer. The interdigital transducer includes split electrodes of paired electrode fingers arranged on the piezoelectric substrate such that a shear horizontal (SH-type) surface acoustic wave is excited on the piezoelectric substrate and is reflected between the two opposing edges. Each of the edges is preferably located at a distance of at least about &lgr;/2&minus;5&lgr;/128 from a center of the paired equipotential electrode fingers, located at the respective outermost portions, in the surface acoustic wave propagation direction, of the interdigital transducer and less than about &lgr;/2 from the center of the paired equipotential electrode fingers, where &lgr; is a wavelength of the SH-type surface acoustic wave excited on the piezoelectric substrate.

Edge reflection type surface acoustic wave filter

An edge reflection type surface acoustic wave device utilizes a Shear Horizontal type surface acoustic wave and includes a surface acoustic wave substrate, and at least two interdigital transducers provided on one main surface of the surface acoustic wave substrate. First and second grooves are formed on the opposite ends in the surface acoustic wave propagation direction of the area where the interdigital transducer is provided. The first and second grooves extend from the one main surface of the surface acoustic wave substrate toward the other main surface thereof without reaching the other main surface. The grooves extend substantially perpendicularly to the surface acoustic wave propagation direction so as to define first and second edges for reflecting the surface acoustic wave. The first and second edges are defined by the inner sideively. walls of the first and second grooves, respectively.

Edge reflection type surface acoustic wave device with grooves or steps at the reflection edges

A transversely coupled surface acoustic wave filter includes a surface acoustic wave substrate having opposing first and second end surfaces, and first and second interdigital transducers provided on the surface acoustic wave substrate. The first and second interdigital transducers define first and second surface acoustic wave resonators which use a wave including a shear horizontal wave as its main component. The first and second surface acoustic wave resonators are connected to define a transversally coupled resonator filter. The filter preferably has a relative dielectric constant E&equals;&isin; /&isin; in the range of about 0 to about 3000 and the electromechanical coupling coefficient K is such that K &middot;&isin; is in the range of about 0 to about 250. Also, the aperture length y is preferably within the range of: 0.945&plus;5.49&times;exp(&minus;E/366) &gE;y&gE;2.46&times;exp(&minus;E/219).

Transversely coupled resonator type surface acoustic wave filter and longitudinally coupled resonator type surface acoustic wave filter

An edge reflection type surface acoustic wave device includes a surface acoustic wave substrate having an opposing pair of edges and at least one interdigital transducer located on the surface acoustic wave substrate. A Shear Horizontal type surface acoustic wave is generated by the interdigital transducer and reflected between the opposing pair of edges. The interdigital transducer is divided into a plurality of sub-IDT portions along a surface acoustic wave-propagating direction. Electrode fingers of the interdigital transducer which are closest to each other between adjacent sub-IDT portions are at the same potential so as not to be excited between the adjacent sub-IDT portions. In addition, when it is assumed that the widths of the outermost electrode fingers in the surface acoustic wave-propagating direction of the interdigital transducer are equal to the widths of the remaining electrode fingers before cutting of the substrate, the edges are arranged such that the edges are cut at a location inside of the center of the outermost electrode fingers in the surface acoustic wave-propagating direction such that a distance between the opposite edges of the substrate is not an integral multiple of &lgr; /2.

Edge reflection type surface acoustic wave device

An edge reflection type surface acoustic wave device includes a surface acoustic wave substrate made of a piezoelectric single crystal and having first and second opposite edges, and at least one interdigital transducer disposed on the surface acoustic wave substrate. The surface acoustic wave device is constructed such that a Shear Horizontal type surface acoustic wave is reflected between the first and second opposite edges. The surface acoustic wave substrate is made of an ion-implanted piezoelectric single crystal substrate.

An edge reflection type longitudinally coupled SAW resonator filter includes a surface acoustic wave substrate having a first end surface and a second end surface which are arranged at opposite ends of the substrate. A plurality of edge reflection, longitudinally coupled resonator filter units are arranged on the surface acoustic wave substrate such that a surface acoustic wave is reflected between the first end surface and the second end surface of the surface acoustic wave substrate. A connecting conductive portion is arranged to electrically connect the plurality of the longitudinally coupled resonator filter units. Each of the longitudinally coupled resonator filter units has a plurality of interdigital transducers aligned in a surface acoustic wave propagating direction. The number of pairs of electrode fingers in the plurality of the longitudinally coupled resonator filter units is equal. In addition, a ratio of the numbers of pairs of the electrode fingers between the plurality of the interdigital transducers in at least one of the plurality of the longitudinally coupled resonator filter units is different from ratios of the numbers of pairs of the electrode fingers between the plurality of the interdigital transducers in the other longitudinally coupled resonator filter units.

Edge reflection type longitudinally coupled saw resonator filter

A surface acoustic wave filter apparatus includes a plurality of stages of multi-mode filters defined by edge-reflection type surface acoustic wave devices and electrically connected in series with each other. The plurality of stages of multi-mode filters are provided on a common piezoelectric substrate and arranged in a direction which is substantially perpendicular to the propagation direction of surface acoustic waves. Ground electrodes are located between the stages of the plurality of stages of multi-mode filters.

Multi-mode edge reflection saw filter device with ground electrodes between stages, duplexer, and communication device

A surface acoustic wave device is constructed to operate using an SH type surface acoustic wave and so that the surface acoustic wave is reflected by two opposite edges of the device. The surface acoustic wave device includes a piezoelectric substrate having first and second main surfaces and the two edges arranged opposite to each other and which connect the first and second main surfaces, respectively, and an interdigital transducer having a pair of interdigital electrodes provided on the first main surface of the piezoelectric substrate and arranged so that the electrode fingers thereof are interdigitated with each other. The electrode fingers of the interdigital electrodes include a plurality of split electrodes, except for the electrode fingers located at the outermost sides in the surface acoustic wave propagation direction. The electrode fingers on the outermost sides have a width that is different from that of the split electrodes.

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Nagaokakyo, Japan

Junya Ago